Phylogenetic diversity is a better predictor of wetland community resistance to Alternanthera philoxeroides invasion than species richness

• Highly biodiversity communities have been shown to better resist plant invasions through complementarity effects. Species richness (SR) is a widely used biodiversity metric but lacks explanatory power when there are only a few species. Communities with low SR can have a wide variety of phylogenetic diversities (PD), which might allow for a better prediction of invasibility.
• We assessed the effect of diversity reduction of a wetland community assemblage typical of the Beijing area on biotic resistance to invasion of the exotic weed Alternanthera philoxeroides and compared the reduction in SR and PD in predicting community invasibility.
• The eight studied resident species performed similarly when grown alone and when grown in eight‐species communities together with the invasive A. philoxeroides. Variation partitioning showed that PD contributed more to variation in both A. philoxeroides traits and community indicators than SR. All A. philoxeroides traits and community indicators, except for evenness index, showed a linear relationship with PD. However, only stem length of A. philoxeroides differed between the one‐ and two‐species treatments, and the diversity index of the communities differed between the one‐ and two‐species treatments and between the one‐ and four‐species treatments.
• Our results showed that in natural or semi‐natural wetlands with relatively low SR, PD may be a better predictor of invasibility than SR. When designing management strategies for mitigating A. philoxeroides invasion, deliberately raising PD is expected to be more efficient than simply increasing species number.

     

Notch pathway plays a novel and critical role in regulating responses of T and antigen-presenting cells in aGVHD

Graft-versus-host disease (GVHD) induced by host antigen-presenting cells (APCs) and donor-derived T cells remains the major limitation of allogeneic bone marrow transplantation (allo-BMT). Notch signaling pathway is a highly conserved cell-cell communication that is important in T cell development. Recently, Notch signaling pathway is reported to be involved in regulating GVHD. To investigate the role of Notch inhibition in modulating GVHD, we established MHC-mismatched murine allo-BMT model. We found that inhibition of Notch signaling pathway by γ-secretase inhibitor in vivo could reduce aGVHD, which was shown by the onset time of aGVHD, body weight, clinical aGVHD scores, pathology aGVHD scores, and survival. Inhibition of Notch signaling pathway by DAPT ex vivo only reduced pathology aGVHD scores in the liver and intestine and had no impact on the onset time and clinical aGVHD scores. We investigated the possible mechanism by analyzing the phenotype of host APCs and donor-derived T cells. Notch signaling pathway had a broad effect on both host APCs and donor-derived T cells. The expressions of CD11c, CD40, and CD86 as the markers of activated dendritic cells (DCs) were decreased. The proliferative response of CD8+ T cell decreased, while CD4⁺ Notch-deprived T cells had preserved expansion with increased expressions of CD25 and Foxp3 as markers of regulatory T cells (Tregs). In conclusion, Notch inhibition may minimize aGVHD by decreasing proliferation and activation of DCs and CD8⁺ T cells while preserving Tregs expansion.     

Hydroxysafflor yellow A (HYSA) inhibited the proliferation and differentiation of 3T3-L1 preadipocytes

Hydroxysafflor yellow A (HSYA), a main component of safflor yellow, has been demonstrated to prevent steroid-induced avascular necrosis of femoral head by inhibiting primary bone marrow-derived mesenchymal stromal cells adipogenic differentiation induced by steroid. In this study, we investigate the effect of HSYA on the proliferation and adipogenesis of mouse 3T3-L1 preadipocytes. The effects of HSYA on proliferation and differentiation of 3T3-L1 cells and its possible mechanism were studied by 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyl tetrazolium bromide spectrophotometry, Oil Red O staining, intracellular triglyceride assays, real-time quantitative RT-PCR, transient transfection and dual luciferase reporter gene methods. HSYA inhibited the proliferation of 3T3-L1 preadipocytes and cell viability greatly decreased in a dose and time dependent manner. HSYA (1 mg/l) notably reduced the amount of intracellular lipid and triglyceride content in adipocytes by 21.3 % (2.13 ± 0.36 vs 2.71 ± 0.40, P < 0.01) and 22.6 % (1.33 ± 0.07 vs 1.72 ± 0.07, P < 0.01) on days 8 following the differentiation, respectively. HSYA (1 mg/l) significantly increased hormone-sensitive lipase (HSL) mRNA expression and promoter activities by 2.4- and 1.55-fold, respectively (P < 0.01), in differentiated 3T3-L1 adipocytes. HSYA inhibits the proliferation and adipogenesis of 3T3-L1 preadipocytes. The inhibitory action of HYSA on adipogenesis may be due to the promotion of lipolytic-specific enzyme HSL expression by increasing HSL promoter activity.     

Accelerating Neuroimage Registration through Parallel Computation of Similarity Metric

Neuroimage registration is crucial for brain morphometric analysis and treatment efficacy evaluation. However, existing advanced registration algorithms such as FLIRT and ANTs are not efficient enough for clinical use. In this paper, a GPU implementation of FLIRT with the correlation ratio (CR) as the similarity metric and a GPU accelerated correlation coefficient (CC) calculation for the symmetric diffeomorphic registration of ANTs have been developed. The comparison with their corresponding original tools shows that our accelerated algorithms can greatly outperform the original algorithm in terms of computational efficiency. This paper demonstrates the great potential of applying these registration tools in clinical applications.     

Retracted: Long noncoding RNA MEG3 inhibits proliferation and migration but induces autophagy by regulation of Sirt7 and PI3K/AKT/mTOR pathway in glioma cells

Glioma is a common primary brain tumor with high mortality rate and poor prognosis. Long noncoding RNA maternally expressed gene 3 (MEG3) is a tumor suppressor in diverse cancer types. However, the role of MEG3 in glioma remains unclear. We aimed to explore the effects of MEG3 on U251 cells as well as the underlying mechanisms. U251 cells were stably transfected with different recombined plasmids to overexpress or silence MEG3. Effects of aberrantly expressed MEG3 on cell viability, migration, apoptosis, expressions of apoptosis-associated and autophagy-associated proteins, and phosphorylated levels of key kinases in the PI3K/AKT/mTOR pathway were all evaluated. Then, messenger RNA (mRNA) and protein expression of Sirt7 in cells abnormally expressing MEG3 were estimated. In addition, effects of abnormally expressed MEG3 and Sirt7 on U251 cells were determined to reveal the underlying mechanism of MEG3-associated modulation. Cell viability and migration were significantly reduced by MEG3 overexpression whereas cell apoptosis as well as Bax and cleaved caspase-3/-9 proteins were obviously induced. Beclin-1 and LC3-II/LC3-I were upregulated and p62 was downregulated in MEG3 overexpressed cells. In addition, the autophagy pharmacological inhibitor (3-methyladenine, 3-MA) affected the effect of MEG3 overexpression on cell proliferation. Furthermore, the phosphorylated levels of key kinases in the PI3K/AKT/mTOR pathway were all reduced by MEG3 overexpression. Sirt7 was positively regulated by MEG3 expression, and effects of MEG3 overexpression on U251 cells were ameliorated by Sirt7 silence. MEG3 suppressed cell proliferation and migration but promoted autophagy in U251 cells through positively regulating Sirt7, involving in the inhibition of the PI3K/AKT/mTOR pathway.     

Ant assemblage composition explains high predation pressure on artificial caterpillars during early night

1. Predator–prey interactions, especially those involving herbivorous insects, are of great importance in maintaining biodiversity. Predation pressure varies temporally in response to prey availability and activity. However, little is known about the patterns and drivers of fluctuations in predation pressure at fine temporal scales. 2. Artificial caterpillars (placed on plant leaves at breast height) were used to assess changes in predation pressure across four time intervals of the day in a monsoonal tropical rainforest in south-west China. The study examined how assemblage composition of arboreal ants, the dominant predators, changed across the same time intervals. The potential linkages between biotic (arboreal ants) and abiotic (temperature and light intensity) factors with predation rate were evaluated. 3. Predation rate on caterpillars during the early part of the night (19.00–01.00 hours) was significantly higher than in the morning, afternoon, or late night. Ant assemblage composition, rather than species richness or total abundance, best explained the variations in predation rate on artificial caterpillars. 4. The results help to strengthen understanding of trophic interactions by demonstrating that predation pressure fluctuates at finer timescales than previously tested, and that a particular set of ant species may play major roles in predation on caterpillars and possibly other organisms.     

Synergistic effect on anti-methicillin-resistant Staphylococcus aureus among combinations of α-mangostin-rich extract,lawsone methyl ether and ampicillin

α-Mangostin-rich extract (AME) exhibited satisfactory inhibitory activities against all tested MRSA strains, with minimum inhibitory concentrations (MICs) of 7·8–31·25 µg ml⁻¹, whereas lawsone methyl ether (LME) and ampicillin revealed weak antibacterial activity with MICs of 62·5–125 µg ml⁻¹. However, the combination of AME and LME showed synergistic effects against all tested MRSA strains with fractional inhibitory concentration index (FICI) values of 0·008–0·009, while the combination of AME and ampicillin, as well as LME and ampicillin produced synergistic effects with FICIs of 0·016–0·257. A time-kill assay against MRSA (DMST 20654 strain) revealed a 6-log reduction in CFU per ml, which completely inhibited bacterial growth for the combinations of AME and LME, AME and ampicillin, and LME and ampicillin at a 8-h incubation, while those against MRSA (2468 strain) were at 10-h incubation. The combination of α-mangostin and LME as well as the combinations of each compound with ampicillin synergized the alteration of membrane permeability. In addition, α-mangostin, LME and ampicillin inhibited the biofilm formation of MRSA. These findings indicated that the combinations of AME and LME or each of them in combination with ampicillin had enhanced antibacterial activity against MRSA. Therefore, these compounds might be used as the antibacterial cocktails for treatment of MRSA.     

Impacts of benzophenone-type UV filters on cladoceran Daphnia carinata

Limnology - The impacts of three commonly used benzophenone-type UV filters including benzophenone (BP), 2-hydroxy-4-methoxy-benzophenone (BP3), and 2-hydroxy-4-methoxy-benzophenone-5-sulfonicacid...